Baicalin protects against heat-induced multiorgan dysfunction via organ-specific protein modulation: integrative in silico and in vivo evidence.

Heatstroke-induced multiorgan dysfunction represents a life-threatening clinical emergency characterized by systemic oxidative stress, inflammation, and metabolic collapse across vital organs. Despite advances in supportive care, there remains a critical lack of multitarget pharmacological interventions that address the underlying molecular pathology. Here, we evaluated baicalin, a naturally occurring flavone glycoside, for its multiorgan protective efficacy against systemic hyperthermia through an integrated computational-experimental framework. Five key heat-responsive proteins-heat shock protein 70 (Hsp70), heat shock protein 27 (Hsp27), aquaporin-1 (AQP1), interleukin-6 receptor (IL-6R), and cytochrome P450 3A4 (CYP3A4)-were identified as therapeutic targets based on their roles in heat-induced stress and organ injury. Molecular docking revealed strong binding affinities (ΔG = -9.3 to -8.5 kcal mol-1), supported by molecular dynamics (MD) simulations (2000 ns) showing conformational stability (root mean square deviation, RMSD < 0.25 nm; 5-8 hydrogen bonds) and favorable molecular mechanics-generalized born surface area (MM-GBSA) binding energies (up to -65.3 kcal mol-1 for Hsp70-baicalin). Principal component analysis (PCA) and free energy landscape (FEL) mapping confirmed thermodynamic stability, while density functional theory (DFT) calculations (highest occupied molecular orbital-lowest unoccupied molecular orbital, HOMO-LUMO gap = 3.45 eV) supported baicalin's electronic reactivity. In vivo validation using a rat whole-body hyperthermia model (42 ± 0.5 °C for 4 h) demonstrated significant attenuation of heat-induced pathology. Histopathological scoring revealed reduced lesion severity in the brain, heart, kidneys, liver, and lungs following baicalin pre-treatment (50 mg kg-1, intraperitoneal). Western blot and densitometric analyses confirmed downregulation of Hsp70, Hsp27, and IL-6R alongside restoration of CYP3A4 (p < 0.05). Complementary absorption, distribution, metabolism, excretion, and toxicity (ADMET) and ProTox-II analyses predicted a high safety margin (LD50 ≈ 5000 mg kg-1; non-hepatotoxic; non-mutagenic). Collectively, these findings establish baicalin as a promising multitarget natural cytoprotective agent and underscore the translational potential of combining computational pharmacology with in vivo disease modeling to accelerate cytoprotective drug discovery.